parker



@with ytatr atrnt @fitte EDWIN AND THOMAS S. PARKER, 0F SGHENECTADY, NEW YORK. Leiters Patent No. 63,745, dated April 9, 1867.

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TO ALL WHOM IT MAY CONCERN:

Ee it known that we,'EDW1N PARKER and THoMas S. PARKER, of Schenectady, in the county of Schenectady, and State of New York, have invented a new and useful Improvement in Balanced Steam Valves; and

we do hereby declare that the following is a full, clear, and exact description thereof, which will enable others skilled in the art to make and use the saine, reference beine had to the accompanying drawings. forming part of' this specification.

This invention relates to the .construction of the sliding valve and to the device whereby the pressure of the steam upon the valve is counterbalanced and theinvention consists in the construction ot' the valve whereby the steam is admitted on its inside, so 'that the pressure on 'the upper and under sides of the valve is nearly balanced, as will be more fully hereinafter' explained. i

` Figure lrepresents a sectional elevation of our valve, through the line z :u ot' iig. 2.

Figure 2 represents a plan or top view.

Similar letters of reference indicate like parts. V

A represents the cylinder, and B the valve. The steam is admitted into a recess, a, below the valve, as represented in the drawing, or into the steam-chest direct above the valve, as in ordinary cases. In the former case. the steam passes through the valve inte the steam-chest. In the latter' it passes from the chest into the valve, and from thencerinto the cylinder. The novelty whichA is claimed is in the construction of the valve. c c are apertures through the valve through whichithe steam passes. C represents a hollow space or cavity in the valve, which is to be always full of steamwhen the engine is running, and which Supplies the ports of the cylinder with steam. a7 c represent the induction ports, and fthe eduction or exhaust port of the cylinder. It will be seen that the interior surface ofthe valve or the upper surface of the cavity C is almost equal to the whole surface, which is subject to down pressure, and that the latter pressure would but slightly preponderate. This diierence would be necessary to keep the valve properly on its seat. The steam-chest and the rod which connects the valve with the rocker-arm, arc'shown in red lines. In the ordinary slide valve the steam ports are uncovered bythe ends et' the valve, past which the steam enters the ports. In our arrangement the steam is admitted to the ports within the valve itself. The cavity C extends the whole width ci' the valve, it being a mere shell containing the small valve D for the exhaust. This exhaust valve D in fact performs the functions oi' the ordinary slide valve, covering and uncovering the steam port as it moves back and forth, and receiving the exhaust steam.

Having thus described our invention, what we claim as new, and desire to secure by Letters Patent, is-

In thevalve B, constructed substantially as herein shown and described, with the cavity C, I claim the apertures c as und for the purposes set forth. v

EDWIN PARKER, THOMAS S. PARKER.

Witnesses WILLIAM Tenn, ALFRED GozzAnD. 

